[Philip Messer]

I pulled all eight spark plugs in my 351 stroked Windsor (392 CI) without scratching a fender or valve cover! (Pretty good for a guy with ten thumbs!) The plugs were a nice coco brown color with gaps ranging form 33 to 40 thou. (First time I had pulled all of the plugs.) I remember reading past Club Cobra threads that concluded the best overall gap was 45 thou. I purchased a new set of like-kind replacement spark plugs (Motorcraft AGSF 32 C), set them at 45 thou and WOW what a difference when I got back on the road!!

OK, I am sold on the 45 thou. gap setting, but what about the spark plug itself? Is Motorcraft the best spark plug for the street? I discovered that NGK and Champion make the same spark plug (as do most likely others). Anyone found any of these spark plugs better/worse than others? And what about the heat range? For street use, should we be using cooler or hotter plugs? Or is the original spark plug that came with the crate engine the best to use?

Phil form Phoenix